Thursday, 29 November 2012

My biggest disagreement with the zero carb community, or rather specifically with it's leader, who say that we are somehow different from all other carnivorousness animals that get very ill if not fed the whole animal (including organs such as liver, and the bones, skin, etc) and are just fed fatty muscle meat instead, and somehow different from our ancestors who went as far as to call organs sacred and sometimes went to extreme lengths to ensure a proper supply of organs, shellfish, and other foods rich in the fat-soluble vitamins, especially for pregnant/lactating women and growing children. Although we are not strictly true carnivores and can survive on an omnivorous diet, we can also survive on a carnivorous one too, but not a herbivore/vegan diet; our ability to adapt in regards to diet is a big reason why we've managed to become the dominant species on planet. But for the sake of this post we will be taking about humans as though we were true carnivores, as this is what zero carb states.

The zero carb philosophy is based on the words of Vilhjalmur Stefansson during his time staying with the Inuit people, his subsequent year-long all meat diet study at Bellevue Hospital, and the words of Owsley Stanley aka 'theBear'; and states that a diet of just fatty muscle meat is not only healthy but optimal, and that organs meats and other animal foods are completely unnecessary. In this post I will show that this is utter fantasy.

The main issue of eating just fatty muscle meat and no other animal foods is the deficiency this will cause. While muscle meat is rich in many vital nutrients it is completely lacking in retinol (vitamin A) which is the biggest concern; but muscle meat is also very low in copper, calcium, magnesium, and sodium, and low in potassium, selenium, vitamins B1 and B5, and the amino acids glycine and proline. These nutrients are easily found in other animal food: Egg yolks, dairy, and liver are rich in vitamin A; liver (except pork liver), kidneys, heart for copper; bone broth for calcium and magnesium (though supplementing magnesium is also advisable due to water filtration); unrefined salt for sodium; potassium salt for potassium; kidneys for selenium; liver, and pork for vitamin B1; liver, kidneys, and eggs for vitamin B5; and gelatin for glycine and proline. In essence, you need to eat the whole animal (or at least liver, and gelatin-rich bone broths in addition to fatty muscle meat, and to a lesser extent kidneys and the other organs) for complete balanced nutrition.

If you read the Bellevue Study, you'll quickly see that Stefansson ate many different organs: "The meat used included beef, lamb, veal, pork, and chicken. The parts used were muscle, liver, kidney, brain, bone marrow, bacon, and fat. While on lecture trips V. S. occasionally ate a few eggs and a little butter when meat was not readily obtainable". When he was recovering from the high-protein experiment, which only lasted two days (where the scientists conducting the experiment wanted to see what would happen if lean instead of fatty meat was eaten (protein was eaten at 45% of total calories, rather than the usual 20%), his food of choice for the recovery was brains fried in bacon grease! You can read the study for yourself here. As Stefansson ate organs and bone marrow and therefore he can't be used as proof that just fatty muscle meat is enough.

When Stefansson lived with the Inuit he did rightly point out that the Inuit did not eat the liver of the animals they killed. Weston Price also stayed with the Inuit, and as he actually tested the foods they ate to see what nutrients they were getting and from where: he remarks that blubber, of which the Inuit eat a great deal, was extremely rich in vitamin, so they didn't need liver as well! Further-more the liver of their prey would be toxic, as it is too rich in vitamin A, many people know that polar bear and dog liver's are toxic too us, all carnivorous animal's live are. Seals, the main food of the Inuit, eat a lot of fish, including the fish's liver, so have a large amount of retinol in their diet; cod liver oil is very rich in vitamin A but not at a toxic levels, the Inuit eat fish livers. The Inuit did NOT avoid eating liver because it is 'too carby' as theBear claims, which is insane as an ounce of liver adds a measly __g of carbs. This means the Inuit have to use other sources for vitamin A than their prey's liver to avoid toxicity, so they go for blubber instead.

Here's a couple of videos showing Inuit people eating every part of the animal they can: here ("I can't wait to eat the brain", ) and here. So Stefansson's claims that the Inuit do not eat any organs and instead feed them to their dogs is clearly not representative.

theBear was the main creator of the modern day ZC idea by posting on the Active Low-Carber forums, about his experience on the zero carb diet. He reports that his diet for the last nearly half century was made up of fatty muscle meat, eggs, butter, cheese, coffee, with occasional protein powders and other animal foods. So even theBear can't be used as an example of the modern day claimes by the zero carb community that all you need is fatty muscle meat and water, as he regularly ate eggs and dairy. My 'beef', as it were, is with pure fatty muscle meat diets.

theBear repeatedly shows that he has limitiedknowledge of nutrition and frequently gets things wrong:

Quote

Analysis

"Vitamins. that is easy, there are virtually no sources of any vitamins to be in vegetation (which is why all vitamin supplements are synthetic), but all are found in abundance in meat. For example no source of A other than animal liver exists."

Vegetables do contain vitamins, you can get supplements made from plants instead of synthetically, but he's right that vitamins are more concentrated in animal foods, they're also more bio-available due to lack of anti-nutrients such as fibre or phytic acid. There are other sources of vitamin A, even restricting to just sources of retinol, which is preformed vitamin A rather than beta-carotene, liver is not the only source: egg yolks and dairy (butter, cream, cheese, etc) are two such examples. But when looking at meat as in a dead animal rather than all animal foods, yes liver is the best source; grass-fed animal fats though will have beta-carotene in them which is what makes grass-fed animal fats yellow, but conversion of beta-carotene to retinol is non-exist in 45% of the population and extremely poor in the rest of the population even when highly deficient in retinol.

"The one meat that needs to be eaten sparingly is liver, which contains a lot of starch (glycogen) and vit. A which is toxic in excess. Excess may be as little as one ounce of the liver of an animal feeding on fish."

100g of beef liver contains 3.9g of carbohydrates, 100g lamb liver 1.8g, this is hardly a lot when all you need for vitamin A requirement is one or two ounces a day. Vitamin A is only toxic if you're deficient in vitamin D. Animals feeding on fish will be getting lots of vitamin A in their diets (fish livers are very rich sources of vitamin A, cod liver oil is one of the most concentrated sources per gram) so their livers will be extremely rich in it, we know that the livers of polar bears and dogs have too much vitamin A for us to eat, but the livers of herbivores are perfectly safe to eat.

"'Excess' dietary protein is broken down and discarded, never converted to glucose except in an emergency- such as under heavy and extensive fasting- and then only after all the stored glycogen in liver and muscle has been converted first. The liver under these circumstances only produces from protein the exact amount necessary to maintain the normal level. Only dietary intake can drive the blood glucose level above your baseline."

Protein is converted to glucose (via gluconeogenesis) all the time, even on a high carb diet and there's plenty of glycogen. The liver can and sometimes does make too much glucose from protein and raises your blood glucose level, many people low/zero carb experience elevated blood glucose levels after eating too much protein. Diabetics have it even worse, as their liver is less sensitive to insulin (or insulin is lacking) and so makes a huge amount of glucose via gluconeogenesis, sometimes such that it uses up all dietary protein and thus leads to muscle wasting. Phinney and Volek's research shows that plenty of glucose can be made from gluconeogenesis, which along with using glycerol from triglycerides (fats) to make glucose, can provide up to 200 grams per day. Those with diabetes can't turn down this production of glucose down, which is why they can experience severe hyperglycaemia even while fasting.

"So long as your body has retained any level of glycogen (the liver usually is about 40% glycogen, plus some is stored in muscles) you will not tear apart proteins for glucose"

So how is the body keeping glycogen level from being completely depleted after years and years? Gluconeogenesis, aka making glucose from proteins, see above point.

We never stop using glucose completely even when fully keto-adapted, parts of the body always need glucose, this is why blood sugar levels are maintained at a stable level even when no carbohydrates are eaten, and why we have a way of making glucose from protein. If you give a drug to reduce blood sugar down too low, we would soon faint and then die. Glucose is vital for life, the question is whether it's better to eat it or make it ourselves (this is of course a topic for another day but the above links discussing the rate of gluconeogenesis on a high/low carb diet points very heavily to it being making it ourselves).

"If the body was able to create glucose on demand from ripping the core out of protein, then why is 100% protein so deadly it can kill you in about a week to ten days? Adding dietary fat or carbs prevents this poisoning. The fact is gluconeogenesis is rare except under two conditions, severe fasting and recovery from starvation-induced bodyfat depletion on a zero carb diet. Then the adipose tissues are re-built by diverting a small amount of blood sugar which stimulates mild gluconeogenesis."

Protein toxicity, or rabbit starvation, is when too much protein is eaten. The toxicity is not from the protein itself but the breakdown products of the protein which accumulate faster than they can be removed from the body. Stefansson experienced this after only too days on a high-protein low-fat carnivore diet.

The last bits makes no sense at all. Adipose (fat cells) would be rebuilt from dietary fat. After every meal the fat you eat is stored in your fat cells (but they can freely leave to supply fuel/energy between meals and overnight as insulin is kept low all the time), too much fat in the blood is also harmful to the body just like too high blood sugar. Blood sugar doesn't stimulate gluconeogenesis, a lack of it does (as in low blood sugar stimulates gluconeogenesis in order to raise blood sugar to a safe level).

The idea that fat tissue, an active regulatory tissue in the body, is simply destroyed and rebuilt on demand is fallacy. This is easily verified in any medical text book since the invention of the microscope.

Also this point is a void anyway, any diet made of 100% of just one nutrient would be fatal, not just protein.

"Glycogen is not depleted by exercise, period. The muscles ONLY use free fatty acids complexed with n-acetylcarnitine to provide the energy to reverse ADP to ATP, no carbs are consumed in this process, either as glucose or as glycogen.

The famous 'wall' hit by runners etc., indicates a problem in mobilising bodyfat in a carb-loading individual once dietary circulating fat is consumed. It does not occur in a keto-adapted meat eater."

Glycogen is depleted in exercise, though when keto-adapted it is used up at a much slower speed and can be refilled by gluconeogenesis easily such that it never appears to decrease. Glucose is used to generate ATP, it enters the Krebs cycle via pyruvate.

The 'wall' is caused by depleted glycogen and has been studied extensively, but he's quite right that that you also need an ability to access your fat stores too. The winner of the last Western States 100, a 100 mile ultra-marathon, was described as low-carb but when actually questioned as to what he ate while running it was revealed that he was some carbs to refill glycogen albeit a fraction compared to the high-carb runners.

Exercise when keto-adapted meaning being able to burn both glycogen/glucose and fats/ketones for fuel at the same time.

Anaerobic exercise always uses glycose/glycogen for fuel, as without oxygen fat/ketones can't be oxidised, the glucose/glycogen is metabolised to lactate aka lactic acid, which will build up in the muscle until the exercise is reduced enough or stopped such that oxygen can being used to metabolise the lactate back into glucose.

And so on...

In a way the whole animal versus just fatty muscle meat argument could be boiled down to a these comparisons:

ZC community

Weston A Price

Based on one group, the Inuit; and the experience of a few people, mostly theBear

Travelled the globe looking at many different cultures and what that had in common

Based on conjecture, no real scientific basis for only fatty muscle meat

All cultures went to great lengths to ensure supply of foods which contained the fat soluble vitamins A, D, and K2, animal protein, and the long chain omega-3 fatty acids EPA and DHA

Says no harm with come to you eating nothing but fatty meat

Photographed results of fat soluble vitamins deficiencies, such as lack of eyes in pigs born to vitamin A deficient mothers

"If it's not in fatty meat, then you don't need it"

Actually tested the foods different people ate to see what nutrients they were getting and from where they got them

Based on the experience of a few decades at most, by a handful of people

Based on the accumulated knowledge of many thousands of years of knowledge by people from all over the world

theBear: no scientific background, frequently gets things wrong

Accomplished scientist who was knowledgeable far beyond his time

If organs (or other animal foods like egg/dairy) aren't needed and just fatty muscle meat is not only sufficient but actually optimal, then why do other carnivorous animals get very sick on just fatty muscle meat, why did primitive cultures put so much importance on organs and other sacred foods even sometimes going to extreme lengths to obtain them.

In nature, the predators who eat first (the alpha wolves, the lion) will go for the abdominal cavity, and organs at once and even fight to defend their choice cuts. Betas will eat the peripheral organs and muscle meat, both will eat fat. Bones will be broken and contents eaten by all. As well scavengers quite often will work the smaller bones the top level predators missed, as well as eat things like the eyes (carnivorous birds especially). The whole animal in nature is essentially picked clean of anything edible by a series of carnivores.

The simple truth is there has never been any carnivorous animal of meat-eating human population who didn't eat the whole animal until very recently. Practically everyone even included a serving of liver a week until the last few decades or so.

Is there some magical difference between modern day zero carbers and every single other carnivorous animal and every single primitive culture? Because unless there is some magical difference then eating a diet of purely fatty muscle meat is highly dangerous? Are zero carbers that arrogant in the status or 'truthiness'of their leaders' a priori proclamations that they are willing to risk serious deficiencies will possibly permanent damage? How arrogant do you have to be to do that?!

In my mind these people are no better than fruitarians who also claim their diet is perfect, that any nutrient not found in fruit/veg is not needed (replace fruit/veg with steak), etc. In fact just go to the table above and replace every instance of 'fatty muscle meat' with 'fruit/veg' and you'll have 90% of what comes out of a fruitarian's ass.

At least the fruitarians have admitted that you need vitamin B12 injections on their diet after people have gotten permanent nerve damage or had their babies die from B12 deficiencies. How long do we have to wait for ZCers or their unfortunate children to go blind from retinol deficiency or even die, before they realise the stupidity of ignoring that fact that certain substances are vital for health, or even just life itself?!

Do you really want to be part of an experiment of which the results are at best unknown and at worst extremely dangerous? No... Then eat your liver and drink your gelatin-rich bone broth, or eat eggs, dairy, or other animal foods.

If you follow a zero carb diet which includes eggs or dairy, but think I'm wrong, don't complain to me, this is about people eating only fatty muscle and no other food, your diet includes nutrients not found in muscle meat so your lack of deficiency doesn't prove just muscle meat is healthy.

I am still looking at how much of each nutrient is needed on a ketogenic carnivore/near-carnivore diet, but the result is highly likely to still include liver, gelatin, bone broth (or other calcium sources), and possibly other organs, eggs, and other animal foods; NOT just muscle meat.

Today on facebook a member of the zero carb community posted to their wall a video (link), saying that the wolves didn't eat the organs, just the meat and fat. When my good friend Danny Albers and I commented to say that the organs clearly had been eaten, even the guts, and that even the filmer mentions that the carcass is "mostly eaten empty", what should happen but our comments removed and both of us banned from his facebook.

This is more than pathetic, it is pure cowardice!

Seriously, this isn't even about what the wolf did or did not eat, this is about freedom of speech and freedom of opinion.

In this day and age of modern communications, we are always going to find people with whom we disagree, but that's no reason to block them. Sure if they're being a menace or trolling you, then fine, but a couple of comments saying you don't agree is nothing!

Do you know who else deletes comments and blocks peoples for posting differing views? DurianRider, fruitarian and leader of the heavily censored site 30bananasaday.com (check out 30bananasadaysucks.com for more on that). This is why I place in my mind many zero carbers and fruitarians in the same category, they both are deluded and can't take criticism, well not even criticism, a couple of comments!

Is it any wonder I have no respect for the zero carb community when they pull stunts like this?

Wednesday, 28 November 2012

To create my last carnivorous diet, I used the USDA RDA as targets for the nutrients. The USDA RDA is based on the nutrient requirements on a high-carb, grain-based diet, and the nutrient requirements on a carnivorous diet are almost certainly different:

Several nutrients are used directly in carbohydrate metabolism, and so these nutrients will have a lower requirement on a carnivorous diet

Some are used in protein and fat metabolism, and more will be needed on a carnivorous diet

Most nutrients interact with each other such that the altered levels for proper carb/fat/protein metabolism means less or more is needed of other nutrients

Phytochemicals such as phytic acid effect the abosrption/ultilisation of nutrients

I will be discussing each nutrient in the context of a carnivorous diet, what they are needed for, what other nutrients effect their absorption and excretion, how much is needed on a carnivorous diet (as best I can calculate), their best sources, and anything else note-worthy.

Some nutrients even without specifically eating foods for that nutrient will have an intake well over the USDA RDA and thus I see little point in examining them as closely as the likelyhood that you will become deficient in these nutrirents is unlikely. I'm more interested in looking at what nutrients we need less of than the USDA RDA, but there are several nutrients which through my research I have discovered good evidence that the USDA RDA is too low and of which we actually need a lot more. Some nutrients I will not give a cRDA (carnivore RDA), as the amount needed is happily supplied from all the other foods in the diet in order to fulfil the other cRDA, such that no real attention/worry is needed for that specific nutrient.

Saturday, 17 November 2012

This blog post is an updated and slightly edited version of on of my 'facebook essays', which were comments written as normal comments in facebook but ended up being really long and more like essays. I saved the links to their original posting and plan to go through them all and update and neaten up, etc, them then post them here. This one has been done first as a friend requested a copy to sent to someone else.

I'm stick and tired of people telling me the body can't detox without 'fruit and vegetables'. So I guess that's why water fasting doesn't work? :P

The body has many systems for detoxing and even makes it's own anti-oxidants which are many many fold more efficient that any from food. One thing the body does need though, for detoxing, is quality protein. The liver is the main detoxifier of the body and requires protein to do so. A good example is Campbell's rat studies, the high-protein rats got PRE-cancerous lesions, but the low-protein rats ALL DIED!

The body's biggest anti-oxidant is glutathione.

Some foods have it but dietary absorption is very poor, we have to make our own. Glutathione is made from cysteine, glutamate, and glycine, and needs the mineral selenium. Cysteine is best found in animal foods, especially organs, and is practically always deficient on a vegetarian/vegan diet. Glycine is the major amino-acid of gelatin (along with proline), and most other proteins are low in glycine. Gelatin's best sources are feet/hooves, skin, heads of animals, made into broth. Glutamate is non-essential and readily available as long as you're eating enough protein, additionally most protein sources are rich in glutamate. Selenium's best animal food source is kidneys, and best plant food source is brazil nuts. Most people don't get enough selenium, additionally the USDA RDA is 55ug, but studies show that 200ug is a much more appropriate intake. Studies on vegetarians/vegans show very low glutathione levels, as the two out of the three amino-acids required to make it are found in animal foods.

Cysteine is a double-edged sword, it's very good for us, but bacteria also use it. Glutathione locks cysteine up so bacteria can't get it it, but our cells can easily unlock it. This is why supplementing cysteine can be dangerous, unless it's as N-acetyl-cysteine which is another 'locked up' form that greatly increases glutathione levels. Other things that boost glutathione levels are raw whey (not powdered), alpha lipoic acid, and milk thistle. Vitamin D also increases brain glutathione levels.

Glutathione is needed to excrete many toxins through bile, to form leukotrienes (which are fatty based signalling molecules formed from arachidonic acid (also only found in animal foods)), it prevents oxidative damage by being a co-factor for glutathione peroxidase AND detoxing methylglyoxal, a by-product of glycolysis (burning glucose for fuel) and lipid peroxidation (from excess PUFAs). Methylglyoxal is linked to arterial atherogenesis and it oxidises LDL.

Low glutathione levels are also strongly implicated in muscle wasting, as seen in cancer, AIDS, sepsis, trauma, burns and even athletic over-training. Supplementing glutathione in AIDS increases survival rates. Disorders such as schizophrenia, depression, and bipolar also feature low glutathione levels and data suggests oxidative damage (from lack of glutathione to protect against oxidation) can be the cause of these.

The second biggest anti-oxidant is uric acid.

Yes, too much causes gout, but the slightly increased levels on a meat heavy diet are good for us. It seems that ascorbic acid (vitamin C) and uric acid have the same functions and are possibly opposed to each other. Those on an all meat diet don't get scurvy and uric acid is likely why, as it has huge anti-oxidant capacity and is increased when you eat a lot of meat. It seems you need a lack of both uric acid and ascorbic acid to get scurvy.

Natural plant food sources of vitamin C have phytochemicals called 'xanthine oxidase inhibitors' that lower uric acid production (as xanthine oxidase produces uric acid from protein), and it seems that the body prefers to use either ascorbic acid or uric acid. This may be why refined fructose is so dangerous, as fructose itself greatly increases uric acid to gout-causing levels. Natural fructose as found in fruit though, has lots of vitamin C and xanthine oxidase inhibitors which will counter-act the uric acid increasing properties of the fructose, but excessive consumption of even natural fructose, not just refined sucrose and HFCS, can lead to gout as the uric acid raising properties of fructose is slightly higher than the uric acid lowering properties from the xanthine oxidise inhibitors in the fruit. The uric acid increase from meat though is not enough on it's own to cause gout though.

[Update: In fact the genetic mutation that means we can't synthesise ascorbic acid makes fructose more fattening and dangerous to us, some scientists theorise that this is done so that we could use fruit to fatten ourselves for cold winters more efficiently; this is bollocks, it's much more likely caused by a lack of dietary fructose rather than abundance. Why on earth (or any other planet with life :P ) would evolution favour a mutation that makes an animal's food dangerous to it? Indeed getting fat before winter can be seen as an advantage for survival but the mutation also means that fructose is more efficient at causing insulin resistance, diabetes, obesity, cancer, gout, etc, none of which would give a survival advantage. A diet high in fruit/fructose for the purpose of getting fat for the winter, when you have this mutation, gives a very high risk of gout, which can be crippling! As our diet changed from a frugivore to a near-carnivore one we lost our ability to handle fructose as well, while finding another substance with which to replace the ascorbic acid. Ascorbic acid is made from glucose, uric acid is made from protein; you can clearly see why we changed out antioxidant as we changed our diet.]

Taking isolated or synthetic ascorbic acid, which lacks the inhibitors, will result in high uric acid and high ascorbic acid levels. The uric acid will not be lowered (as it's not the ascorbic acid that does that), and so gout will still occur. Some vitamin c supplements have added 'bioflavonoids' or 'quercetin', both of which are xanthine oxidase inhibitors and with thus lower uric acid levels. I'm not aware of any problems caused by having high uric and ascorbic acid levels at the same time though, just that plain vitamin c will not help lower uric acid levels in of itself.

This really emphasises why foods sweetened with HFCS (or even sugar) are so dangerous. It seems nature supplies to antidote with the poison in regard to fruit. But then that begs the question of why eat the poison in the first place? It seems uric acid is a safer option over ascorbic acid as it doesn't come with so much 'baggage'.

Uric acid is a HUGE reason why Arctic explorers eating just meat did not get scurvy but those sneaking biscuits got it (and recovered when the biscuits where thrown away), also sailors (whose diet was mostly biscuits, rum, and salt beef)... Phytic acid is a xanthine oxidase inhibitor! Thus they got scurvy due to the lack of uric and ascorbic acid. With sailors the scurvy was remedied through fresh fruit (or sauerkraut in the case of the Germans), supplying vitamin C. But they would've got equally good results by removing the biscuits from their diet (and possibly also the rum as alcohol and fructose are metabolised the same way by the liver, but the sailors would never allow that!).

Thus scurvy is not a disease of lack of vitamin c but a combined lack of ascorbic acid and insufficient uric acid. Supply either will cure scurvy, thus gout suffers are highly unlikely to suffer from scurvy as well. Removing xanthine oxidase inhibitors from a diet rich in fresh protein will cure and prevent scurvy. Adding fresh fruit or vegetables to a sailors diet did not always cure scurvy though, it's quite likely there needs to be a combined effort between uric and ascorbic acid. The fruits and vegetables would supply some ascorbic acid but also xanthine oxidase inhibitors, in addition to those from their biscuit rations, such that the addition ascorbic acid is not sufficient to counter-act the simultaneous decrease in uric acid.

Because natural plant sources of vitamin C often have xanthine oxidase inhibitors, this means that they are poor at preventing scurvy, as they lower uric acid more than they increase ascorbic acid in terms of anti-scorbic potential. Animal sources of vitamin c, including raw liver, spleen, adrenal glands, and blubber, do not have xanthine oxidase inhibitors and so will not reduce uric acid levels; this means they are safe to include when eating a carnivore or meat-heavy diet. Additionally pure synthetic ascorbic acid, without 'bioflavonoids' or 'quercetin' is also safe to take.

It must be noted that there seems to be a difference between fresh and dry meat/protein, as diets of only fresh meat/protein will never produce scurvy, but there have been two cases of scurvy associated with calorie-restricted pemmican-only diets. Pemmican is made of ground dried lean meat mixed with equal amounts of rendered fat. Both these pemmican-only diets that resulted in scurvy though were highly restricted in calories/amount. One case had someone eating only very small amounts of pemmican as their sole diet, while also dry fasting daily (not drinking during the day); the other features chronic diarrhoea from before a carnivore diet was started that continued no matter what the person ate (that is, it wasn't dietary related), although the person was eating plenty of pemmican the diarrhoea meant very little was absorbed and thus yielded again a restricted diet. The presentation of these cases of scurvy were unusual as they did not experience many of the usual symptoms such as loose teeth, the most prominent symptom in both cases were extensive bruising of the legs from damaged/burst capillaries under the skin. Pemmican itself is not the problem though as there is evidence from one family, consisting of a man, woman, and two young boys, who have eaten nothing but pemmican for many years without problems; the two boys were weaned from breast milk straight onto pemmican and ate no other foods. This family though ate large amounts of pemmican, equivalent to 3-4 pounds of fresh meat daily. The difference is amount or calories, the drying process may damage some of the anti-scorbic properties compared to fresh meat, such that larger than expected amounts of pemmican are needed on a dry:fresh weight or calorie basis. Pemmican was traditionally used as a travel food and thus only for short periods of up to a couple of months, and those doing heavy physical work, such as building railways, thus they would have consumed large amounts which would have been sufficient to prevent scurvy. If one is going to eat a pemmican-only diet for a longer period than a couple of months, make sure you eat plenty and drink enough water; under two months doesn't pose a risk, as does eating a mixed pemmican and fresh meat diet.